Yes, lights on. But that isn't your problem. Your problem is that you have made the squirrels wary by using the snap traps. Can't do that. Use live traps.

Now you'll need to disguise those traps before you can reliably get them. Go thru both my squirrel pages, read EVERYTHING, all the popups and even the pictures often have text in them. Once you do that, you'll be better prepared for your enemy. Throw those snap traps away, they're not even good for rats.

Get another 1040 trap. Use it outside, where your squirrels patrol. Disable it, keep it baited up, let them go in and out and get whatever they want.

Then you can disguise the trap in the attic and start getting results.